Presentation Transcript

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DEPARTMENT OF PROSTHODONTICS SEMINAR TOPIC
ON
POSTERIOR
PALATAL SEAL

POSTERIOR PALATAL SEAL :

POSTERIOR PALATAL SEAL Introduction
The denture must be seal all along its boundaries.
The seal is known as peripheral seal.
The posterior palatal seal is the part of this.
The drapping of tissues over the buccal and lingual borders provides an effective seal in these region.

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The seal along the posterior border of maxillary denture is known as posterior palatal seal.
However the posterior border of maxillary denture requires the different kind of seal because at the posterior aspect of denture in the area of the soft palate there are no cheek tissues to seal the denture border.

DEFINITION :

DEFINITION The soft tissues at or along the junction of the hard and soft palate on which pressure with in the physiological limits of the tissues can be applied by a denture to aid in the retention of the denture.
LOCATION
The posterior palatal seal is formed through both hamular
notches and across the palate over the vibrating line.
FUNCTION
Retention
Prevents food accumulation beneath the denture
Maintain contact with the moving soft palate and reduces the patient’s awareness and thus reduces gag reflex.
As the posterior denture border will closely approximate the soft palatal tissues and compensates for the volumetric shrinkage that occurs during the polymerization of methyl methacrylate resin.

COMPONENTS OF POSTERIOR PALATAL SEAL :

COMPONENTS OF POSTERIOR PALATAL SEAL PTERYGOMAXILLARY SEAL
This is the part of the posterior palatal seal
that extends across the
hamular notch
The pterygomaxillary seal is placed in hamular notch
it is located behind the maxillary tuberosity.
It is located using a T-burnisher, it is moved along
posteriorily untill a soft depression is felt
POST PALATAL SEAL
This is the part of posterior palatal seal that
extends
between the two maxillary tuberosities.

BOUNDARIESOF POSTERIOR PALATAL SEAL :

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VIBRATING LINE
The imaginary line across the posterior part
of the palate marking the division between
the movable and immovable tissues of the
soft palate which can be identified when the
movable tissues are moving.

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ANTERIOR VIBRATING LINE
It is an imaginary line
located at the
junction of attached tissues
overlying the
hard palate and
the movable tissue of the
immediately adjacent soft palate.
LOCATED BY –
Valsalava Maneuver
Patient is asked to say “ah” with short
vigorous bursts.

POSTERIOR VIBRATING LINE :

POSTERIOR VIBRATING LINE It is an imaginary line
located at the junction
of the soft palate that shows
limited movements
and the soft palate that shows marked
movements.
LOCATED BY –
It is located by asking the patient to say “ah” in
short but non vigorous fashion.

POINTS SHOULD BE REMEMBER WHILE RECORDING THE PPS :

POINTS SHOULD BE REMEMBER WHILE RECORDING THE PPS Presence of palatine torus
Position of fovea palatina
Presence of mid palatine fissure
Patient with thick ropy saliva

CONVENTIONAL TECHNIQUE :

CONVENTIONAL TECHNIQUE Stage of recording
After final impression
Method
Locate the hamular notches
↓
Marked with indelible pencil
↓
Posterior vibrating line marked by
asking patient
to say “ah” non vigorously.
↓
The hamular notch and
posterior vibrating line are
joined using indelible pencil

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The marking transferred to master cast.
↓
Anterior vibrating line marked
by asking the patient to
Perform valsalva manuver.
↓
The area between anterior
and posterior vibrating line
is scored on the cast.

BOUCHER’S TECHNIQUES :

BOUCHER’S TECHNIQUES Stage of recording – During jaw relations
Method
Palpate hamular notch and marked with indelible pencil.
↓
Patient ask to say “ah” and vibrating line marked with indelible pencil.
↓
The earlier markings joined with this
↓

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Trial denture base inserted and line
is transferred to it
↓
Excess base plate removed
↓
Placed on cast and posterior
limit of base plate marked
↓
V – Shaped groove is carved on the cast

FLUID WAX TECHNIQUE :

FLUID WAX TECHNIQUE Stage of recording
After making the final impression.
Method
Zinc oxide eugenol or plaster impression are preferred
↓
Both the vibrating lines are marked in the mouth and transferred on to the impression
↓
Korrecta wax no. 4,Lowa wax,
H-L physiologic paste or
Adaptol may be used
↓
The molten wax is painted between the two lines

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The patient’s head should
be downward by 30°
↓
The impression reinserted in
the mouth and hold for 4 to 6 min
↓
The wax should terminate in a
knife edge near the anterior
vibrating line
↓
Excess wax is trimmed off

EXTENDED PALATAL TECHNIQUE :

EXTENDED PALATAL TECHNIQUE Stage of recording
After border moulding
Method
Denture border is extended 8.2 mm beyond the anterior vibrating line
↓
Head is fixed downward 30°
↓
Application of green stick compound to the seal area
↓
An angular depression is seen in the compound

STICK COMPOUND TECHNIQUE :

STICK COMPOUND TECHNIQUE Stage of recording
During border moulding before final impression made
Method
Application of stick compound on the tray between both
The vibrating lines
↓
Pressed gently in the mouth

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↓
Excess material beyond the anterior vibrating line is trimmed off
↓
The region is flamed lightly and the process is repeated
↓
Dull appearance of compounds indicates positive contacts

ERRORS IN RECORDING PPS :

ERRORS IN RECORDING PPS Over extension
Under extension
Under postdamming
Over postdamming